Regulatory Matters - Schedule of Additional Significant Riders Associated with Virginia Power Projects (Parenthetical) (Detail) $ in Millions		1 Months Ended			9 Months Ended
		Jul. 31, 2023 USD ($)	May 31, 2023 USD ($)	Apr. 30, 2023 USD ($)	Sep. 30, 2023 USD ($) Project Program Agreement
Rider T1 | Virginia Electric and Power Company
Public Utilities, General Disclosures [Line Items]
Total revenue requirement	[1]				$ 879
Rider T1 | Operating Segments | Virginia Electric and Power Company | Virginia Regulation
Public Utilities, General Disclosures [Line Items]
Total revenue requirement					369
Rider T1 | Operating Segments | Virginia Electric and Power Company | Virginia Regulation | Transmission Component Of Virginia Powers
Public Utilities, General Disclosures [Line Items]
Total revenue requirement					510
Rider SNA | Virginia Electric and Power Company
Public Utilities, General Disclosures [Line Items]
Total revenue requirement	[2]				50
Rider SNA | Operating Segments | Virginia Electric and Power Company | Virginia Regulation | First Phase of Nuclear Life Extension Program
Public Utilities, General Disclosures [Line Items]
Projected capital investment					$ 1,200
Rider CE
Public Utilities, General Disclosures [Line Items]
Public utilities number of power purchase agreements | Agreement					13
Public utilities number of small scale solar project | Project					1
Rider CE | Virginia Electric and Power Company
Public Utilities, General Disclosures [Line Items]
Total revenue requirement	[3]				$ 137
Public utilities number of solar generation projects | Project					5
Rider U | Virginia Electric and Power Company
Public Utilities, General Disclosures [Line Items]
Total revenue requirement	[4]				$ 74
Rider U | Virginia Electric and Power Company | Virginia Regulation | Previous Phase
Public Utilities, General Disclosures [Line Items]
Projected capital investment					72
Rider U | Virginia Electric and Power Company | Virginia Regulation | Seven Phase
Public Utilities, General Disclosures [Line Items]
Projected capital investment					78
Rider GV | Virginia Electric and Power Company
Public Utilities, General Disclosures [Line Items]
Total revenue requirement	[5]				132
DSM Riders | Virginia Electric and Power Company
Public Utilities, General Disclosures [Line Items]
Total revenue requirement	[6],[7]				107
DSM Riders | Virginia Electric and Power Company | Virginia Regulation
Public Utilities, General Disclosures [Line Items]
Amount of cost cap recovery					$ 150
DSM Riders | Operating Segments | Virginia Electric and Power Company | Virginia Regulation | Energy Efficiency Program
Public Utilities, General Disclosures [Line Items]
Number of new energy efficiency programs | Program					4
Rider GV | Virginia Electric and Power Company
Public Utilities, General Disclosures [Line Items]
Total revenue requirement	[5]				$ 135
Rider GV | Virginia Electric and Power Company | Rate Year Beginning April 2024
Public Utilities, General Disclosures [Line Items]
Total revenue requirement					144
Rider GV | Operating Segments | Virginia Electric and Power Company
Public Utilities, General Disclosures [Line Items]
Total revenue requirement					$ 148
Base Rate Case | Virginia Electric and Power Company | Virginia Regulation
Public Utilities, General Disclosures [Line Items]
Total revenue requirement		$ 350	$ 351	$ 350
Rider DSM | Virginia Electric and Power Company | Virginia Regulation
Public Utilities, General Disclosures [Line Items]
Public utilities energy efficiency program cost exceed percentage					15.00%

[1] Consists of $510 million for the transmission component of Virginia Power's base rates and $369 million for Rider T1.

[2] Virginia Power requested approval of cost recovery of approximately $1.2 billion through Rider SNA for the first phase of nuclear life extension program which includes investments through 2024. In April 2022, Virginia Power, the Virginia Commission staff and certain interested parties filed a proposed stipulation recommending that costs incurred after February 2022 associated with the first phase of the nuclear life extension program for North Anna be deferred and requested for recovery in a subsequent Rider SNA filing.

[3] Associated with five solar generation projects, one small-scale solar project and 13 power purchase agreements in addition to previously approved Rider CE projects. In addition, Virginia Power seeks Virginia Commission approval to consolidate Rider PPA with Rider CE and to end Rider PPA in April 2024.

[4] Consists of previously approved phases of Rider U. In August 2023, the Virginia Commission approved Virginia Power's request to extend the rider for the rate year beginning April 2023 through June 2024.

[5] The total revenue requirement requested is based on an estimated retirement of Greensville County in 2058, consistent with the current estimated useful life of the facility. Virginia Power also provided an alternative approach based on an estimated retirement of Greensville County in 2045, which if utilized would result in a revenue requirement of $144 million and $148 million for rate years beginning April 2024 and April 2025, respectively.

[6] Associated with an additional four new energy efficiency programs, one new demand response program and four new program bundles with a $150 million cost cap, with the ability to exceed the cost cap by no more than 15%.

[7] In May 2023, Virginia Power filed a notification with the Virginia Commission to combine Riders R, S and W, which have an aggregate revenue requirement of $351 million, into base rates effective July 2023 in accordance with legislation enacted in Virginia in April 2023.